1. Field of the Invention
This invention relates to image signal processing apparatus and methods.
2. Description of the Prior Art
It has been proposed to manipulate an image signal in the spatial domain by mapping words of the signals into a memory in such a manner that, when the mapped image is read out from the memory, it will have been manipulated by virtue of the mapping process in a manner dictated by the mapping function that is employed in carrying out the process. Such a technique may, for example, be employed in the creation of digital video effects.
The mapping process may involve compression and/or rotation of the image. Moreover, the extent of compression and/or rotation may vary from area to area of the mapped image. As is explained in more detail below, both compression and rotation may lead to aliasing, which will cause degradation of the image.